Improvement in duplex safety-valves



T. HARANG.

Duplex Safety-Valves.

No. 135,220, Patenred1an.28,1873.

UNITED STATES PATENT CDEEICEo THOPHILE HAB-ANG, OF BANANA GROVE PLANTATION, PARISH OF LA FOUROHE, LOUISIANA.

IMPROVEMENTIIN DUPLEX SAFETY-VALVES.

Specification forming part of Letters Patent No. 135,%20, dated January 28, 1873.

To all whom it may concern:

Be it known that I, THEOPHILE HARANG, of

j boiler is also lifted, and thus temporarily closes the steam-exit through the valve-hole, causing a rupture or explosion. In accordance with this theory my improved safety-valve is so constructed that gradually, as the pressure increases, more and more steam is allowed to escape from the boiler, and, vice versa, gradually less and less as the pressure decreases in the boiler. l

In order to describe my invention more fully I refer to the accompanying drawing forming a part of this specification.

Figure I is a side view of my improved safety-valve attached to the top of a steam-boiler. Fig. II is a longitudinal vertical section of the same.

To the top of a steam-boiler, A, is connected, by the pipe a, the safety-valve B. The valve B is constructed of a pipe or cylinder, b, into both ends of which the valve-seats c c are secured. To the center of the valve-seat c is fastened a pipe, d, which serves as a guide tor the hollow rod or pipe e, to one end of which the valve f is attached, and to the other end the piston g. h and ii are springs of different strength, 7L being ot' a strength to resist the daily Workingpressure in the boiler, t' somewhat stronger.

The steani generated in the boiler A iiows, through the pipe a, into the interior of the safety-valve B, pressing against the pistons g g, which are held in their places until the press ure in the boiler exceeds, first, the resisting power of the spring It; and, second, in case ot' still higher and suddenly-increasing pressure, the resisting power of the spring i'. By the motion of the pistons g g by the over-pressure in the boiler the valves fj' are also moved from their seats c c, presenting an opening through which the steam escapes from the holes n n in the pipes or hollow rods c c, which are so placed that more or less steam will escape in proportion to the pipe c being' pushed further out.

7- and l are elbows attached to the ends oi' The safety-valve B, constructed and arran ged to operate substantially as described, and for the purpose hereinbcfore set forth.

THOPI-IILE HARANG.

Witnesses l?. FORTUNE FAZENDE, ADAM BAREIos. 

